Safety device for electric circuits.



Withesses:

E. H. JAGOBS. SAFETY DEVICE FOR ELECTRIC 'O IRGUITS.

APPLICATION FILED 170.22, 1910.

' v Patented Dec. 3, 1912.

B C D i i I l l Inventer: Ernest ijjacobs, by Hisflttarneg.

T '0 all whom. itmay concern;

a specification.

- provision of means whereby a circuit can be opened, closed, and generally controlled in switch will be opened. I also rovide means provide means whereby the main switch;

" 'n'nrrnn s'rirrns Parana? neuron nnnrs'r in moons, or scnnnncmnr, new YORK, ASSIGNOB TO GENERAL nLncrnro COMPANY, AC RPORATION OF NEW YORK.

SAFETY DEVICE FOR ELECTRIC CIRCUITS.

, Specification of Letters Patent.

Patented nee-3,1912.

Application filed August 22, 1910. Serial No. 578,373.

Be it known that I, ERNEST H. Jaooss, a citizen of the. United States, residing at Schenectady, countyof Schenectady, State of New York, have invented certain new and usefulImprovements in Safety Devices for Electric Circuits, of which the following is This invention relates to the control of electric circuits and has for its ob ect the a. reliable, simple and efiicient manner.

. My invention relates more specifically to means for controlling the-circuit by means of a circuit controller or switch which may in turn be controlled from a point somewhat remote from the switch itself. --l'n the operation of one or more electric motors in industrial plants, such as mills, machine shops, and the like, it is frequently desirable to have all the motors controlled from a. main switch located at the switchboard. This main switch is then controlled by a number of'controlswitches located at the. various motors, so that the-operator may, by means of a control switch,open .the main switch and stop all the motors.

. One of the objects of my intention isto after it has once been opened by theope'r w ator, cannot be again ClOSMlBXCGPhZby "the same operatoror' with his consent.

In carrying out my invention I provide a main switch for controlling one or more motors and a cont-r01 switch for each motor, the arrangement bein such that if any one of the control switches is actuated the'main whereby the main switch is ocked a ainst closing when the operator opens it, an cannot be closed until the operator again actuates the control switch. The main switch is preferably manually closed, sothat after the operator has opened the main switch from a remote point he must go to the switch to close it. The arrangement for preventing the closure of the switch is preferably an electromagnetic devicewhich locks some part of the switch, as, for instance, the lie-voltage mechanism, against closure and can only be released by the control switch which locked it. The control switches may be key switches which can only be operated by a particular key in the hands of the operator, so that the main switch cannot be closed except by the use of the key that opened it. In this way the operator protected against the acci-- dental. starting of the motor when,he may be in a position to be injured thereby.

Other objects of my invention will appear in the'course of the following specification, in which I have shown my invention embodied in concrete form for purposes of illustration.

Referring to the drawing, in which I have showirmy invention in a somewhat diagrammatic way, represents the main circult controller or switch for opening and closing the three phases B, C, audit) of the.

supply circuit. 1 have shown my invention in connection with a three phase System merely for purposes of illustration but it is obvious that it is equally applicable to any other system.

For purposes of illustration I have shown. In a somewhat C()Il\'(.I1l'.-l()flll way a manually closed'oil switch having a toggle arrangement for latchingit in closed position. Any

suitable type of switch provided will, however, serve my purpose. -The switch which I have employed consists of three bridging contacts 10, l1, and 12, one for each phase, carried by the frame 13 which is raised and lowered by means of the arm 14; pivoted to the frame at 15 and to a stationary support at 16. The operating handle 17 is likewise pivoted at 16 and is connected with the arm 14 by toggle mechanism 1.8. A pivoted latch 19 holds the operating handle 17 in closed posit-ion. A trip lever 20 pivoted at 2.1 is mounted on a fixed. support so that the.end 22 will engage and knock out the toggle mechanism, while the opposite end 2' engaged by pivoted latch 24 to hold it away from the toggle mechanism against the 'tension of the spring 2-5. The lie-voltage coil 26 provided with a core 27 is arranged to drop upon the failure of voltage and trip the latch in a well-known manner.

In order to prevent-the core 2'7 from being raised, after it has once been dropped, i provide a locking device consisting of a core 28 having a projection 29'which moves into the path of the projection on the core 2'? and acts as a barrier. The locking turojection 29 is normally held out of locking position.

by means of a spring 30 and is moved. into locking position by the energizing cithe coil 31, which; moves the. p1 0]6Ct10I1 against I. the tension of the spring into the position shown in dotted lines, This, of course, happens when the core 27 is in the down position. In order to control the main switch from a rem ote' point or points, I provide the control switches 32. One of these switches is preferably provided at 'each motor M controlled by the main switch A, which --motors may be located at various points around the plant or mill. The switches are connected in multiple and are preferably of the locking type which can only be actuated to either open or close the circuit by means of a particular key. which is in the hands of the operator. 1

The arrangement of circuits and the mode of operation are'as follows: Assuming the parts to be in the position shown in full lines in the drawing, the main circuit will beclosecl and the' motors running. If now, an operator at any of the motors desires, for any reason, to stop the'motor, he inserts his key in the switch 32 andturns it so as to close the control circuit, at his switch. This various modifications thereof will sug has the eil'ect of short-circuiting the novoltage coil 26, WlllCl'l is normally connected across the line, and also energizing the coil.

31. This causes the core -27 to drop and trip the main switch and at the same time moves the core 28 into locking position. When the core 27 trips the toggle mechanism'thcswitch contacts are moved into position shown in dotted lines, thereby opening the main circuit. In order to close the switch it is first necessary that-the operator again actuate his switclr32 to cleenergize the coil -81:"S He- 'may then close the switchby means of the operatin handle 17. .To close theswitch latch 19 is raised and the handle 1! moved to the leftto straighten the toggle. The handle is then moved to the right, lifting the arm ]4 through the straightened toggle and therel'i v raising the frame 13 and closing the switch. This cannotbe done, however, unless the no voltage core 27 is raised. since otherwise the end 22 of the trip lever will he in engagethe operator that operated it. This prevents the operator from being injured by the accidental starting of his motor while he is unprepared for it. While I have shown it as embodied in concrete form for purposes of illustration, it should he understood that I do= not limit my invention thereto, since est themselv s to those skilled in the art w thout departing from the spirit of my invention,- the scope of which is set fort! in the annexed vclaims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with a main switch, of electrically controlled means 'for locking" said switch against closure, a magnet for controlling the opening .of said main switch, and a control swltch for controlling sa1d magnet and the lockingmeans.

2. The combination with a main switch, of a plurality of electromagnets; means controlled by said magnets for openin said switch and locking the same against 0 osure,

and a control switch for controlling said ma gn ets.

3. The combination with a main switch, a

of means for locking said switch against closure, a magnet for actuating said locking means to permit the switch to he closed, a. n'lagnct for controlling the opening of said main switch, and a control switch for both of said magnets.

4. The combination with a mainswitch and a no-voltage magnet for controlling the same, of electrically controlled means for locking said switch against closure, and a control switch for deenergizing the novoltage magnet and actuating the locking means.

5. The combination with a main switch and a no-voltage magnet for controlling the same, of electrically controlled means for locking said switch against closure, and a control switch for -denergizing the novoltage magnet and simultaneously actuating the locking means.

6. The combination with a main switch and a no-voltage device-for controlling the Same, of electrically controlled locking means for the no-voltage device, and an auxiliary switch for" controlling the no-voltage device and the locking means.

7. The combination with a main-switch and a ire-voltage device for controlling the same, of electrically controlled" locking means for the no-voltage device, and an auxiliary switch for simultaneously controlling the no-voltage-magnet and'the locking means.

8. The combination with a main switch and a no-voltage device for controlling the same, of electromagnetic lockingmeans for the no-voltage device. and a. control switch for deenergizing the no-voltage device and simultaneously actuating the locking means. 1

9. The combination with a main switch and a no-voltage device for controlling the same. of electron'iagnetic locking means for the no-voltage device biased to inoperative position. and a control switch '-for dee'nero'usly energizing'the 'locking means.

10mm combinati n with a switch gizing the no-voltage deviceand simultanea no.-voltage provided ranged to be .adeener'glzlng the n0voltage device'and sif voltage magnet ating said loc multaneously actuating the 'l'ooki'ng means. 11. The combination with a main switch provided with operatin mechanism arranged to be latched in c 0 a no-voltage magnet trippinw said mechanism to open'the switch upon the failure'of voltage,- of electromagnetielockin means for said switch, and a control switci for denergizing the noand simultaneously actuhing means to lock the main switch against closure, r

12.:Thecombination with a mainswitch provided with means for latching the same in closed position, of a no-voltage solenoid 'having a core arranged to drop and open the sed .position and for automatically switch, an electrically controlled member movable into the path of said core to lock it against npward movement and a control switch for deenergizing the solenoid and simultaneously actuating the locking memher.

13. The combination with a main switch provided with means for latching the same in closed position, of a no-voltage solenoid having a core arranged to drop and open the switch, a locking member for said core biased to inoperative position, electromagnetic means for moving said member i to the path of said core'to lock it against movement. and a control switch for deinergiving the solenoid and simultaneously moving the said member to locking position.

In witness whereof, I have hereunto set my hand this 20th day of August, 1910.

. ERNEST H. JACOBS. Witnesses .BENJAMIN B.' HULL,

HELEN Onronn.

Copies of this patentmay be obtained for m cents each, by addressing the "Commissioner of Patents,

' Washington, D. C." 

